The current debate about the nature of early Jerusalem centers on the date—or dates—of the construction of the Stepped-Stone Structure. While Margreet Steiner argues that the Stepped-Stone Structure is made of two separate architectural elements built 200 years apart, Jane Cahill contends that the substructural terracing and the superstructural stepped mantle (both are in orange in the drawing, above right) were both built in the 13th/12th century B.C.E. and are structurally connected.
Starting with the photo above, we see the meeting point, or the straight line of masonry known as an architectural seam (1), where, according to Cahill, the stepped mantle (2) meets the mid-level terraces’ stone- and soil-filled compartments (3). In the photo above, taken before archaeologist Yigal Shiloh cut a probe into a sealed area of the stepped mantle’s fill, a woman is standing on the lowest courses of the mantle exposed by Shiloh. (The same area is shown in both photos and is circled in the drawing. A wall  at the top center of each photo, is the northeastern corner of Ahiel’s House, the lowest courses of which were built on top of the Stepped-Stone Structure in the tenth century B.C.E. A seventh-century B.C.E. wall  runs across the foreground of both photos.)
In a later photo (below), many of the limestone blocks of the stepped mantle have been removed, revealing the rubble core inside (6). (The southern boundary of Shiloh’s probe is marked 1, and the northern boundary 7; the probe stopped when it reached large stones  that could not be removed.) The excavators also revealed the spine wall segments (9) and rib walls (10) that make up the mid-level terrace compartments, and their rubble core (11). Because the stepped mantle’s rubble core is bonded to (that is, structurally integrated with) the terrace fill, and because the 13th/12th-century B.C.E. pottery found in the stepped mantle’s rubble core is identical to the pottery from the terrace fills, Cahill argues that both elements were built at this time, with the terrace serving as a substructure for the mantle.